The aim of this study is to describe the associations between various host characteristics and yeast colonization; biofilm and phospholipase production in diabetic patients. The study was conducted between January 2003 and June 2003 in Abant Izzet Baysal University, Duzce, Turkey. One hundred and fourty five diabetic patients were included to the study. All oral and faecal specimens were placed on Sabourand dextrose agar with chloramphenicol and gentamicin. All isolates were identified with classic methods and carbohydrate assimilation patterns using API 20 CAUX. C. dubliniensis isolates were identified by CHROM agar Candida and chlamydospore formation according to the referral to the literature. Biofilm and phospholipase production was assessed by using previously described methods. The most common colonized species were C. albicans in oral and faecal cultures. C. dubliniensis was isolated in four oral cultures of the patients. Dental prosthesis, tooth brushing, older age, antibiotic use in the previous two weeks were found to be the significant factors for the oral yeast colonization. Younger age, smoking, shorter duration of diabetes, hospitalization in the last year and antibiotic use in the previous two weeks were found to be the significant factors for the faecal yeast colonization. Biofilm production was found to be positive in nine cases of oral and seven of faecal isolates. Phospholipase production was determined to be positive in 18 cases oral and 14 of faecal isolates. In conclusion, glycaemia control and other diabetic factors are not effective for yeast colonlizing. There was not any significant correlation between biofilm and phospholipase production and host characteristics in yeast colonization. Oral hygiene may be an effetive for decreasing the oral colonization in diabetic patients.